Temporary roof systems have been used in the entertainment business for many years. These systems, however, are not immune to a dangerous collapse as was experienced a few years ago at the Indiana State Fair. These prior art temporary roof systems are typically anchored to the ground with a series of guy cables that run from the in place roof position to an anchor/ballast point. Although the instructions and engineering reports that are provided with the lighting and or staging platforms and systems require that all guy cables and structural rods should be pre-tensioned to a set value depending on the requirements for each location, one of the more difficult issues that must be handled, is how to properly set the pre-tension, and perhaps even more importantly is how to be sure that the pretension is maintained once properly set. Most techniques for setting the pretension use electronic devices that are put between the tension cable or structural tension rod and the anchor or connection point during assembly or set up. The tension in the cable or structural rod is properly set, and then the device is removed. A major problem with this technique is that once the tension is set, the tension must be removed before the measuring device can be removed.